Shoulder and neck straps are often used for carrying a load. For example, a shoulder strap could be used for carrying a golf bag or a duffel bag. Similarly, neck straps are used for carrying a variety of musical instruments such as a saxophone. Such loads are often carried for a long time. Poorly designed shoulder and neck straps become uncomfortable when carrying heavy loads for a long time. For example, rubbing the strap against a person's body for a long time may cause skin irritations. Old carrying straps were poorly designed or made of inelastic material, such as leather. Therefore, shocks or stress from carrying a load for extended periods of time while moving, e.g., during long walks, were absorbed by the body of the person carrying the load causing pain and discomfort.
Newer more comfortable straps use soft stretchable material, such as neoprene, which provides a cushioning effect and functions as a shock absorber. Neoprene distributes shocks caused by the load more uniformly. However, because a long piece of neoprene has elasticity similar to a rubber band, the object being carried bounces when a single strap of neoprene is used as a shoulder or a neck strap.
Such an excessive up and down bounce causes uncomfortable changes in the load pressure upon a person's shoulder or neck. The point where the strap comes in contact with the shoulder or the neck bears the brunt of the stress caused by the bounce. The more a person moves or the heavier the weight of the load, the larger the bouncing effect which increases shoulder or neck stress and discomfort. Therefore, the cushioning and shock absorbing effect of the neoprene is counteracted by an excessive bouncing which is very uncomfortable and inconvenient. Furthermore, under a heavy load, the overstretched neoprene will tear. To prevent excessive stretching and tearing, an additional strap is used, which is stronger and less stretchable than neoprene.
FIG. 1 shows such a conventional shoulder strap 100 having a neoprene strap 120 and an additional strap 130 which is attached to the neoprene strap 120 by stitches 140 at spaced intervals. The neoprene strap 120 is usually wider than the additional strap 130 so that the load carried by the strap 100 is distributed over a larger area. In addition, the neoprene strap 120 is usually in contact with the shoulder since it is soft and provides a cushioning effect. That is, the additional strap 130 is an upper strap.
The additional strap 130 is formed from a strong fabric such as nylon or other elastic webbing and is attached to the neoprene strap 120 to form loops 150, as shown in FIG 1b. Alternatively, instead of the additional strap 160, a neoprene strap 170 forms loops 180, as shown in FIG. 2. As shown in FIG. 3, when the strap 100 is stretched under a heavy load, the loops 150, 180 (FIGS. 1 and 2) become taut and the additional strap 190 carries the load. This prevents over-stretching or tearing of the neoprene strap 195.
However, such straps 100 neither minimize the bouncing effect of neoprene, nor maximize distribution of the stress along the entire strap. This is particularly a problem when the carried load is heavy, or movement is involved for a long time. Examples include carrying a golf bag during a lengthy golf game, hiking on a rough terrain, long distance walking or carrying and playing a musical instrument for an extended duration while rapidly moving with the rhythm of music.
A further disadvantage of the loops 150, 160 is the ease with which the loops may inadvertently hook onto protrusions thus tearing the strap or causing the bearer of the strap to lose balance and fall. An object of the present invention is to overcome these disadvantages.
It is a further object of this invention to provide a neoprene carrying strap constructed so that the strap is strong and capable of carrying heavy loads with a minimum bounce and a maximum comfort without using loops formed between the neoprene strap and an additional strap.
Another object of the present invention is to decrease the weight bearing surface area of the neoprene strap that comes in contact with a user's shoulder or neck and reduce the stress at the points of contact between the strap and the shoulder or neck.
Yet another object of the present invention is to better distribute the weight along the strap.